Introduction to Color - Brown University
Introduction to Color - Brown University
Introduction to Color - Brown University
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CS123 | INTRODUCTION TO COMPUTER GRAPHICS<br />
High Dynamic Range (3/3)<br />
<br />
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<br />
To avoid the inevitable, lossy compression that occurs when squeezing a<br />
huge DR taken by a camera in<strong>to</strong>, typically, 255 discrete intensity bins, cut<br />
the DR in<strong>to</strong> n sub-intervals and encode each in<strong>to</strong> its own separate image.<br />
Then use a function <strong>to</strong> emphasize the most representative sub-interval and<br />
either clamp the values <strong>to</strong> a min and max I value or allow a little<br />
discrimination of values outside the chosen sub-interval. This function is<br />
called the <strong>to</strong>ne map.<br />
Expensive displays with many more intensity levels specially designed for<br />
HDR images produce incredibly rich images. For example, LG has developed<br />
LCD moni<strong>to</strong>rs claiming contrast ratios of 5,000,000:1!<br />
(http://www.lgsolutions.com/__downloads/pdf/eb2242t041232pr.pdf)<br />
Individually modulated LED pixels allow for true blacks, “infinite” contrast ratios<br />
Andries van Dam<br />
<strong>Color</strong> 23/57
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